Ablation catheter tips and catheters

Abstract

Disclosed herein are ablation catheter tips and catheters, and catheter ablation methods, wherein a same channel within the catheter may be simultaneously used both for applying suction and attaching a target tissue to the ablation electrode, and for expelling a coolant introduced into the catheter via a second channel, fluidly coupled thereto.

What we claim is: 
     
         1 . An ablation catheter tip comprising
 a tip body, having a proximal tip body end and a distal tip body end; an inlet channel, having a proximal inlet channel end and a distal inlet channel end, said inlet channel being longitudinally disposed within said tip body;   an outlet channel, having a proximal outlet channel end and a distal outlet channel said outlet channel being longitudinally disposed within said tip body;   a suction port, located at said distal tip body end and fluidly coupled to said distal outlet channel end; and   an ablation electrode positioned at said distal tip body end; wherein said suction port is configured to secure a target tissue, at a tissue ablation site on the target tissue, to said ablation electrode by applying a vacuum force via said outlet channel when said distal tip body end is proximate to or in contact with the target tissue; and   wherein said inlet channel and said outlet channel are fluidly coupled at said distal tip body end such that the fluid coupling is maintained when said suction port is covered, thereby facilitating propagating a fluid from said inlet channel to said outlet channel and expelling the fluid via said proximal outlet channel end, when the vacuum force secures (i) said ablation electrode to the tissue ablation site and (ii) tissue, adjacent to the tissue ablation site, to said suction port.   
     
     
         2 . The ablation catheter tip of  claim 1  wherein said distal tip body end is configured to induce direct and/or indirect thermal coupling between said ablation electrode and a coolant fluid present at said distal inlet channel end, at said distal outlet channel end, and/or in between said channels at said distal tip body end, and thereby to controllably effect a temperature of said ablation electrode by propagating the coolant fluid at a controllable introduction temperature via said inlet channel and said outlet channel, through said distal tip body end. 
     
     
         3 . The ablation catheter tip of  claim 1 , wherein said inlet channel and said outlet channel are fluidly connected via an opening, duct, or recess. 
     
     
         4 . (canceled) 
     
     
         5 . The ablation catheter tip of  claim 1 , wherein said inlet channel extends between said proximal tip body end and said distal tip body end and wherein said outlet channel extends between said proximal tip body end and said distal tip body end. 
     
     
         6 . (canceled) 
     
     
         7 . The ablation catheter tip of  claim 1 , wherein said suction port at least partially circumscribes said ablation electrode. 
     
     
         8 . The ablation catheter tip of  claim 7  wherein said tip body and said inlet channel are tubular, and said outlet channel is defined by said tip body and inlet channel, and comprises a space between said tip body and said inlet channel. 
     
     
         9 . The ablation catheter tip of  claim 8  wherein said inlet channel further comprises an inlet channel cap, mounted on said distal inlet channel end; and at least one fluid opening, located at said distal inlet channel end, wherein said ablation electrode is positioned in/on said inlet channel cap, such as to be at least partially exposed, and wherein said fluid opening fluidly connects said inlet channel to said outlet channel. 
     
     
         10 . The ablation catheter tip of  claim 9  wherein said at least one fluid opening comprises two or more fluid openings, being annularly disposed about said inlet channel. 
     
     
         11 . The ablation catheter tip of  claim 7  further comprising an inlet tube longitudinally disposed within said tip body, extending from a proximal inlet tube end to a distal inlet tube end; and an inner core longitudinally disposed within said inlet tube;
 wherein said outlet channel is defined by said tip body and said inlet tube, and comprises a first space between said tip body and said inlet tube; 
 wherein said inlet channel is defined by said inlet tube and said inner core, and comprises a second space between said inlet tube and said inner core; 
 wherein said tip body extends distally farther than said inlet tube; 
 wherein said inner core extends distally at least as much as said tip body; and wherein said ablation electrode is positioned on/in a core tip of said inner core. 
 
     
     
         12 . The ablation catheter tip of  claim 6  further comprising:
 a second inlet channel, having a proximal second inlet channel end and a distal second inlet channel end, said second inlet channel being longitudinally disposed within said tip body; 
 a second outlet channel, having a proximal second outlet channel end and a distal second outlet channel end, said second outlet channel being longitudinally disposed within said tip body; and 
 a second suction port, located at said distal tip body end and fluidly coupled to said distal second outlet channel end; 
 wherein said distal tip body end comprises four recesses, each of said recesses extending from a respective proximal inlet channel end to a respective distal outlet channel end, such as to circumscribe said ablation electrode, said recesses being configured to maintain fluid connectivity between said inlet channels and said outlet channels when said recesses, said inlet channel ends, and said suction ports are covered at a distal tip body extremity of said distal tip body. 
 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The ablation catheter tip of  claim 1 , for use in treatment of atrial fibrillation. 
     
     
         16 . The ablation catheter tip of  claim 1 , wherein said ablation electrode is radially, axially, longitudinally moveable relative to said distal tip body. 
     
     
         17 . (canceled) 
     
     
         18 . An ablation catheter comprising:
 an elongate member, being flexible, having a proximal member end and a distal member end;   an inlet channel, having a proximal inlet channel end and a distal inlet channel end, at least a distal portion of said inlet channel being longitudinally disposed within said elongate member;   an outlet channel, having a proximal outlet channel end and a distal outlet channel end, said outlet channel being longitudinally disposed within said elongate member;   a suction port mounted on said distal outlet channel end;   a vacuum port, mounted on said proximal outlet channel end; a fluid inlet port mounted on said proximal inlet channel end; and an ablation electrode positioned at said distal member end; wherein said fluid inlet port is configured to be fluidly coupled to a fluid source;   wherein said vacuum port is configured to be fluidly coupled to a vacuum source;   wherein said suction port is configured to secure a target tissue, at a tissue ablation site on the target tissue, to said ablation electrode by applying a vacuum force via said outlet channel when said distal member end is proximate to or in contact with the target tissue; and   wherein said inlet channel and said outlet channel are fluidly coupled at said distal member end such that the fluid coupling is maintained when said suction port is covered, thereby facilitating propagating a fluid from said inlet channel to said outlet channel and expelling the fluid via said vacuum port, when the vacuum force secures (i) said ablation electrode to the tissue ablation site and (ii) a tissue, adjacent to the tissue ablation site, to said suction port.   
     
     
         19 . The ablation catheter of  claim 18 , wherein said distal member end is configured to induce direct and/or indirect thermal coupling between said ablation electrode and a fluid present at said distal inlet channel end, at said distal outlet channel end, and/or in between said channels at said distal member end, and thereby to controllably effect a temperature of said ablation electrode by propagating the fluid at a controllable introduction temperature via said inlet channel and said outlet channel, through said distal member end. 
     
     
         20 . (canceled) 
     
     
         21 . A catheter ablation method comprising:
 inserting into a subject's body a catheter comprising   a catheter tip with an ablation electrode positioned on/in a distal end thereof;   an inlet channel and an outlet channel both extending along the catheter until the catheter tip distal end and fluidly coupled at the catheter tip distal end; and   a suction port mounted on the catheter tip distal end and fluidly coupled to the outlet channel;   wherein the fluid coupling of the inlet channel and outlet channel at the catheter tip distal end is maintained when the suction port is covered;   positioning and orienting the catheter tip, such that the ablation electrode faces a tissue ablation site on a target tissue in a body cavity;   securing the ablation electrode to the tissue ablation site by applying a vacuum force along the outlet channel, thereby covering the suction port with a tissue, adjacent to the tissue ablation site, and fluidly sealing the catheter tip from the body cavity;   propagating an irrigant through the inlet channel and the outlet channel, via the catheter tip distal end, wherein the irrigant washes against the adjacent tissue covering the suction port; and   ablating the tissue at the tissue ablation site.   
     
     
         22 . The catheter ablation method of  claim 21 , wherein the irrigant is a coolant and wherein the catheter tip distal end is configured such that heat generated by the ablation electrode is transferred to the coolant when the coolant flows through the catheter tip distal end, thereby effecting a temperature of said ablation electrode in said step of propagating the irrigant. 
     
     
         23 . (canceled) 
     
     
         24 . The ablation catheter method of  claim 23 , further comprising, prior to said step of ablating, testing for a presence of blood in the coolant expelled via the inlet channel, if the presence of blood persists
 significantly decreasing the flow of the coolant;   switching off the vacuum force; and   repeating said step of positioning and orienting and subsequent steps.   
     
     
         25 . The ablation catheter method of  claim 24 , further comprising, following said step of ablating, monitoring a temperature of said ablation electrode, if the temperature exceeds a threshold temperature
 switching off the current;   increasing the flow of the coolant; and   switching on the current again.   
     
     
         26 . The ablation catheter method of  claim 21 , further comprising, following said step of ablating, if there remain tissue ablation sites that have not been ablated, repeating said step of positioning and orienting the catheter tip and subsequent steps with respect to another tissue ablation site. 
     
     
         27 . The ablation catheter method of  claim 21 , for use in treatment of atrial fibrillation.